docs: def new_stat(self):
          """Look at the key and value that the user has entered into the stat
          configurator, and set them on the currently selected
          entity.
  
          """
          key = self.ids.newstatkey.text
          value = self.ids.newstatval.text
          if not (key and value):
              # TODO implement some feedback to the effect that
              # you need to enter things
              return
          try:
              self.proxy[key] = self.engine.unpack(value)
          except (TypeError, ValueError):
              self.proxy[key] = value
          self.ids.newstatkey.text = ''
          self.ids.newstatval.text = ''